274 THE entomologist's record. 



until they have attained their utmost development. (3). A fluid 

 passes equally between the upper and lower membranes as they are 

 rolled out, to prevent friction. (4). The rapid and equal evaporation, 

 from the surface of the wing, of the fluid when it has done its work. 

 The so-called aneurism appears to be, rather a collection of super- 

 fluous fluid in the terminal cells of the wing, than to have any real 

 connection with the nervures. Of course, injury, by which the fluid 

 would be artificially stopped in its course, would produce a somewhat 

 similar appearance. — J. W. Tutt. December^ 1890. 



The Differentiation of Cidaria russata (truncata) and 

 IMMANATA. — I am quitc unable, after examining some hundreds of 

 these species, to find any distinctive character in the upper wing 

 markings, but I am not aware that an attempt has been made to 

 distinguish C. truncata from C. immmiata by the markings of the lower 

 wings. With regard to the six specimens enclosed:^ — No. i with the 

 black median band is from Devonshire, and was common in August, 

 1889. Nos. 2 and 3 are from the Island of Lewis (Scotland); these 

 three I call C. immanata, distinguishing them by the angular line of the 

 under wing. No. 4 is from the same locality as No. j, and Nos. 5 and 6 

 are from Lewis (the same as Nos. 2 and 3) ; these three I call tru/icafa, 

 and distinguish them by the rounder waved line of the under wings. In 

 forms I, 2, and 3 the angle is decidedly an acute angle, while in 4, 5, 

 and 6 it forms an obtuse angle. In the latter cases, the upper part of 

 the line is toothed, which is not the case with immanata. This year, I 

 am breeding from both forms, but, at the same time, I invite criticism 

 on the opinions above expressed. — H. Tunaley, Erdington Hall, 

 Birmingham. April 25//;, i8go. 



I scarcely like to offer an opinion on Mr. Tunaley's Cidaricx. C. 

 russata taken here, shows either no line, or only the faintest possible 

 trace of one on the upper side of the secondary wings, though generally 

 distinct on the under side ; and on looking through mine, I must say, 

 the angle appears to be more obtuse in nearly every instance, still they 

 are not like Mr. Tunaley's, and with perhaps the exception of No. 4, I 

 should take his specimens to be all immanata. At what time of the 

 year were they taken ? Russata is double-brooded, and appears here in 

 May and September, whilst immanata is single-brooded, occurring only 

 in July. — P. Russ, CuUeenamore, Sligo. May 21st, 1890. 



The larvae of Cidaria immanata and russata were differentiated by 

 the Rev. J. Hellins, in the JSnt. Mo. Mag., vol. i., p. 165. I do not 

 know the larva of immanata myself, for although I have tried many 

 batches of eggs, I could never get any to hatch; they have always dried 

 up in the winter. Russata I have reared from eggs over and over 

 again. In Yorkshire, the two species are distinct enough in the imago 

 state, and russata, in my experience, very rarely runs to those 

 imma7iata-Y\\ie forms you so often get in the south. In my series of 

 44 riissata and 45 immanata, where the line on the hind wing shows at 

 all, it is acute-angled in imma7iata, and obtuse-angled in russata, 

 excepting perhaps in one specimen of immanata (not from the West 

 Riding), where the line is neither acute nor very obtuse but between 

 the two. In many of my slate coloured Yorkshire specimens though 

 1 Exhibition Box, No. 7 basket. — Ed. 



